Formation and characterization of fluid lipid bilayers on alumina.
Fluid lipid bilayers were deposited on alumina substrates with the use of bubble collapse deposition (BCD). Previous studies using vesicle rupture have required the use of charged lipids or surface functionalization to induce bilayer formation on alumina, but these modifications are not necessary with BCD. Photobleaching experiments reveal that the diffusion coefficient of POPC on alumina is 0.6 microm (2)/s, which is much lower than the 1.4-2.0 microm (2)/s reported on silica. Systematically accounting for roughness, immobile regions and membrane viscosity shows that pinning sites account for about half of this drop in diffusivity. The remainder of the difference is attributed to a more tightly bound water state on the alumina surface, which induces a larger drag on the bilayer.
Mager
Morgan D
MD
Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
Almquist
Benjamin
B
Melosh
Nicholas A
NA
D000535:Aluminum; D000537:Aluminum Oxide / Q000032:analysis*; D002621:Chemistry / Q000379:methods; D004058:Diffusion; D004867:Equipment Design; D008051:Lipid Bilayers / Q000032:analysis* / Q000737:chemistry; D008055:Lipids; D008856:Microscopy, Fluorescence / Q000379:methods; D015233:Models, Statistical; D010087:Oxides / Q000737:chemistry; D010713:Phosphatidylcholines / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014783:Viscosity
D008051:Lipid Bilayers; D008055:Lipids; D010087:Oxides; D010713:Phosphatidylcholines; D000535:Aluminum; D000537:Aluminum Oxide; C028694:1-palmitoyl-2-oleoylphosphatidylcholine